[Boost-users] [asio] clang++ duplicate symbol error when compiling http server2 example

Subject: [Boost-users] [asio] clang++ duplicate symbol error when compiling http server2 example
From: Dane Springmeyer (blake_at_[hidden])
Date: 2010-07-24 14:46:38

I'm building boost trunk (r64316) using clang++ on mac os x 10.6.

The standing library build/install went well, but I hit this error when trying to build one of the boost::asio examples:

$ cd libs/asio/example/http/server2
$ ../../../../../bjam toolset=clang

[...snip...]

clang-darwin.compile.c++ ../../../../../bin.v2/libs/asio/example/http/server2/clang-darwin-2.8/debug/threading-multi/win_main.o
clang: warning: argument unused during compilation: '-O0'
In file included from win_main.cpp:13:
In file included from ../../../../../boost/asio.hpp:20:
In file included from ../../../../../boost/asio/basic_datagram_socket.hpp:20:
In file included from ../../../../../boost/asio/basic_socket.hpp:19:
In file included from ../../../../../boost/asio/basic_io_object.hpp:20:
In file included from ../../../../../boost/asio/io_service.hpp:684:
In file included from ../../../../../boost/asio/impl/io_service.hpp:18:
../../../../../boost/asio/detail/service_registry.hpp:38:15: warning: unknown pragma ignored [-Wunknown-pragmas]
#  pragma GCC visibility push (default)
              ^
../../../../../boost/asio/detail/service_registry.hpp:47:15: warning: unknown pragma ignored [-Wunknown-pragmas]
#  pragma GCC visibility pop
              ^
2 warnings generated.
common.mkdir ../../../../../bin.v2/libs/thread/build/clang-darwin-2.8/debug
common.mkdir ../../../../../bin.v2/libs/thread/build/clang-darwin-2.8/debug/threading-multi
common.mkdir ../../../../../bin.v2/libs/thread/build/clang-darwin-2.8/debug/threading-multi/pthread
clang-darwin.compile.c++ ../../../../../bin.v2/libs/thread/build/clang-darwin-2.8/debug/threading-multi/pthread/thread.o
clang: warning: argument unused during compilation: '-O0'
clang-darwin.compile.c++ ../../../../../bin.v2/libs/thread/build/clang-darwin-2.8/debug/threading-multi/pthread/once.o
clang: warning: argument unused during compilation: '-O0'
clang-darwin.link.dll ../../../../../bin.v2/libs/thread/build/clang-darwin-2.8/debug/threading-multi/libboost_thread.dylib
common.mkdir ../../../../../bin.v2/libs/system/build/clang-darwin-2.8/debug
common.mkdir ../../../../../bin.v2/libs/system/build/clang-darwin-2.8/debug/threading-multi
clang-darwin.compile.c++ ../../../../../bin.v2/libs/system/build/clang-darwin-2.8/debug/threading-multi/error_code.o
clang: warning: argument unused during compilation: '-O0'
clang-darwin.link.dll ../../../../../bin.v2/libs/system/build/clang-darwin-2.8/debug/threading-multi/libboost_system.dylib
clang-darwin.link ../../../../../bin.v2/libs/asio/example/http/server2/clang-darwin-2.8/debug/threading-multi/server
ld: duplicate symbol __ZN5boost4asio6detail14do_throw_errorERKNS_6system10error_codeE in ../../../../../bin.v2/libs/asio/example/http/server2/clang-darwin-2.8/debug/threading-multi/io_service_pool.o and ../../../../../bin.v2/libs/asio/example/http/server2/clang-darwin-2.8/debug/threading-multi/connection.o
clang: error: linker command failed with exit code 1 (use -v to see invocation)

    "clang++"   -o "../../../../../bin.v2/libs/asio/example/http/server2/clang-darwin-2.8/debug/threading-multi/server" "../../../../../bin.v2/libs/asio/example/http/server2/clang-darwin-2.8/debug/threading-multi/connection.o" "../../../../../bin.v2/libs/asio/example/http/server2/clang-darwin-2.8/debug/threading-multi/io_service_pool.o" "../../../../../bin.v2/libs/asio/example/http/server2/clang-darwin-2.8/debug/threading-multi/mime_types.o" "../../../../../bin.v2/libs/asio/example/http/server2/clang-darwin-2.8/debug/threading-multi/posix_main.o" "../../../../../bin.v2/libs/asio/example/http/server2/clang-darwin-2.8/debug/threading-multi/reply.o" "../../../../../bin.v2/libs/asio/example/http/server2/clang-darwin-2.8/debug/threading-multi/request_handler.o" "../../../../../bin.v2/libs/asio/example/http/server2/clang-darwin-2.8/debug/threading-multi/request_parser.o" "../../../../../bin.v2/libs/asio/example/http/server2/clang-darwin-2.8/debug/threading-multi/server.o" "../../../../../bin.v2/libs/asio/example/http/server2/clang-darwin-2.8/debug/threading-multi/win_main.o" "../../../../../bin.v2/libs/thread/build/clang-darwin-2.8/debug/threading-multi/libboost_thread.dylib" "../../../../../bin.v2/libs/system/build/clang-darwin-2.8/debug/threading-multi/libboost_system.dylib"    -g

Does anyone have suggestions or workarounds?

Thanks,

Dane